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MAP kinases, MPK9 and MPK12, regulate chitosan-induced stomatal closure
Mohammad Abdus Salam1, Fabien Jammes, Mohammad Anowar Hossain
1Graduate School of Natural Science and Technology, Okayama University, 1-1-1 Tsushima-naka, Okayama 700-8530, Japan.
Bioscience, Biotechnology, and Biochemistry
|September 14, 2012
Summary
Chitosan triggers stomatal closure through MPK9 and MPK12. These mitogen-activated protein kinases are essential for this plant defense response, involving reactive oxygen species and calcium signaling.
Area of Science:
- Plant physiology
- Molecular biology
- Biochemistry
Background:
- Plant defense mechanisms are crucial for survival.
- Stomatal closure is a key response to external stimuli.
- The role of specific mitogen-activated protein kinases (MAPKs) in chitosan signaling is not fully understood.
Purpose of the Study:
- To investigate the involvement of MPK9 and MPK12 in chitosan-induced stomatal closure.
- To elucidate the signaling pathways downstream of chitosan perception.
Main Methods:
- Utilized MAPKK inhibitor PD98059 to block signaling.
- Examined chitosan-induced stomatal closure in wild-type and mpk9 mpk12 mutant plants.
- Measured reactive oxygen species production, cytosolic alkalization, and cytosolic Ca(2+) oscillations.
Main Results:
- Chitosan-induced stomatal closure was inhibited by PD98059.
- Stomatal closure was impaired in the mpk9 mpk12 double mutant but not in single mutants.
- Chitosan triggered reactive oxygen species production, cytosolic alkalization, and Ca(2+) oscillations in mpk9 mpk12 mutants.
Conclusions:
- MPK9 and MPK12 are critical components of the signaling pathway for chitosan-induced stomatal closure.
- These MAPKs mediate key early signaling events including ROS production and calcium oscillations.
- MPK9 and MPK12 play a coordinated role in plant defense responses to chitosan.
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